Experimental study of nonclassical teleportation beyond average fidelity

TL;DR

This paper experimentally demonstrates that certain entangled states can produce non-classical teleportation channels even when their average fidelity is below the classical threshold, challenging traditional benchmarks.

Contribution

It provides a complete experimental characterization of new quantum witnesses that certify non-classical teleportation beyond average fidelity limits.

Findings

All entangled states can be certified to produce non-classical teleportation with refined witnesses.

Non-classical teleportation can be achieved with states below the average fidelity threshold.

Experimental validation of quantum witnesses under different noise conditions.

Abstract

Quantum teleportation establishes a correspondence between an entangled state shared by two separate par- ties that can communicate classically and the presence of a quantum channel connecting the two parties. The standard benchmark for quantum teleportation, based on the average fidelity between the input and output states, indicates that some entangled states do not lead to channels which can be certified to be quantum. It was re- cently shown that if one considers a finer-tuned witness, then all entangled states can be certified to produce a non-classical teleportation channel. Here we experimentally demonstrate a complete characterization of a new family of such witnesses, of the type proposed in Phys. Rev. Lett. 119, 110501 (2017) under different con- ditions of noise. Furthermore, we show non-classical teleportation using quantum states that can not achieve average teleportation fidelity above the classical limit. Our results have fundamental implications in quantum information protocols and may also lead to new applications and quality certification of quantum technologies.